1. Field of the Invention
The present invention relates to a fluid pressure driving apparatus for switching a contact of gas insulated switchgear, and in particular, to a combined type fluid pressure driving apparatus for driving a circuit breaker and a disconnecting switch.
2. Description of the Related Art
In recent years, a gas insulated switchgear has been mainly used in switchgear for electric power. The gas insulated switchgear is constructed in a manner that many switches are arranged in a metal housing container filled with an insulating gas. Various type of switchgears have been proposed such that a gas insulated disconnecting switch is interposed between a power circuit breaker and any two busbars, between two busbars, between the power circuit breaker and a grounding contact or between the power circuit breaker and a power transmission system.
The typical conventional gas insulated switchgear has been disclosed in U.S. Pat. No. 5,841,087, and a disconnecting switch of the gas insulated switchgear will be described below with reference to FIG. 14 and FIG. 15. FIG. 14 is a front sectional view showing a conventional gas insulated disconnecting switch, and FIG. 15 is a side sectional view taken along a line Bxe2x80x94B of FIG. 14.
As shown in FIG. 14, a disconnecting switch 200 is received in a grounding metal container 201, which is filled with an insulating gas, e.g., SF6 gas. An upper portion of the grounding metal container 201 is formed with first and second attachment flanges 203 and 204, and a first stationary electrode 205 is fixed to the first attachment flange 203 via an insulating spacer. Likewise, a second stationary electrode 206 is fixed to the second attachment flange 204. Namely, these stationary electrodes 205 and 206 are fixed in a state of being electrically insulated from the grounding metal container 201.
Further, as shown in FIG. 15, a lower portion of the grounding metal container 201 is formed with a third attachment flange 208, and a side portion thereof is formed with a fourth attachment flange 209. A third stationary electrode 210 electrically connected to the grounding metal container 201 is fixed to the third attachment flange 208, and a metallic cover 211 is attached to the fourth attachment flange 209. A hollow insulating cylinder 212 extending toward the grounding metal container 201 is fixed to the cover 211, and a drive shaft 213 is inserted into a hollow portion of the insulating cylinder 212. The drive shaft 213 is extended from the outside of the grounding metal container 201 to the inside thereof, and penetrates through the cover 211 while airtightly keeping the insulating gas.
In FIG. 14 and FIG. 15, first to third cylindrical movable electrodes 215 to 217 individually pair with the first to third stationary electrodes 205, 206 and 210 so that first to third contacts 218 to 220 are formed. Further, the movable electrodes 215 to 217 are electrically connected to a current terminal 223 by current application via a sliding contact (not shown) and a shielding element container 222.
The current terminal 223 is connected with another switching device, e.g., a circuit breaker. A main bus conductor is connectable to the stationary electrode insulated from the grounding metal container 201, that is, the first and second stationary electrodes 205 and 206. Thus, the first and second contacts 218 and 219 perform a function as busbar or main bus line select disconnecting switch. Further, the third stationary electrode 210 making short-circuit with the grounding metal container 201 has a ground potential; therefore, the third contact 220 functions as a ground system.
By the way, a gearbox 225 for making a switching operation of the contacts 218 to 220 is received in the metal container 222. The gearbox 225 includes first to third cams 226, 230 and 233, and first to sixth levers 227, 228, 231, 232, 234 and 235. More specifically, the first cam 226 is connected to the first movable electrode 215, and the first and second levers 227 and 228 are arranged so as to hold the first cam 226 between them. The second cam 230 is connected to the second movable electrode 216, and the third and fourth levers 231 and 232 are arranged so as to hold the second cam 230 between them. The third cam 233 is connected to the third movable electrode 217, and the fifth and sixth levers 234 and 235 are arranged so as to hold the third cam 233 between them.
Further, the gearbox 225 drives three movable electrodes, that is, first to third movable electrodes 215 to 217 so as to separate and close the paired first to third stationary electrodes 205, 206 and 210, and thereby, makes the switching operation of the first to third contacts 218 to 220.
The first movable electrode 215 is connected with the first cam 226, and the paired first and second levers 227 and 228 are fixed to the drive shaft 213 at an angle different from each other so as to convert a rotating motion of the drive shaft 213 into a reciprocating motion. Further, the levers 227 and 228 of the first cam 226 are individually provided with a pin at their distal end portion. Both sides of the first cam 226 are formed with a circular-arc groove, and the pin of each distal end of the levers 227 and 228 is slidably inserted into the above groove.
The first cam 226 constructed as described above functions as a cam mechanism for converting a rotary driving force of the drive shaft 213 into a linear reciprocating motion. Therefore, the first cam 226 converts a rotary driving force of the drive shaft 213 into a linear reciprocating motion, and then, transmits it to the first movable electrode 215. When the rotary driving force is transmitted to the first movable electrode 215, the first movable electrode 215 makes a linear reciprocating motion so as to carry out a switching operation of the first contact 218.
In this case, the first cam 226 is formed with a thin and long slot 236 (as shown in FIG. 14) having a width such that the drive shaft 213 can pass through there. The drive shaft 213 passes through the slot 236, and thereby, this performs a function as one fulcrum for the linear reciprocating motion of the first cam 226.
On the other hand, the second and third movable electrodes 216 and 217 include the same cam mechanism as the above-mentioned first movable electrode 215, and make the same linear reciprocating motion.
The gearbox 225 is rotated when a driving force is transmitted to the drive shaft 213 from an operating mechanism section (not shown) arranged at the outside of the grounding metal container 201 in the drive shaft 213 of the disconnecting switch 200. The above operating mechanism section and the gearbox 225 constitute a driving system for switching and driving the first to third contacts 218 to 220.
In the conventional driving apparatus, the first to third contacts 218 to 220 are switched and driven by the driving system including the operating mechanism section and the gearbox 225. More specifically, when the operating mechanism section is driven, the drive shaft 213 of the gearbox 225 is rotated by receiving the driving force, and then, the first lever 227 to the sixth lever 235 are rotated with the rotation.
Then, each distal pin of the rotating first and second levers 227 and 228 moves along the cam groove of the first cam 226. Likewise, each distal pin of the rotating third and fourth levers 231 and 232 moves along the cam groove of the second cam 230, and further, each pin of the rotating fifth and sixth levers 234 and 235 moves along the cam groove of the third cam 233.
The first lever 227 to the sixth lever 235 and the first cam 226 to the third cam 233 interact with each other, and thereby, it is possible to convert the rotating motion of the drive shaft 213 into a linear reciprocating motion. The rotary driving force of the drive shaft 213 thus converted is transmitted to the first to third movable electrodes 215 to 217.
By the driving force thus transmitted, the first movable electrode 215 moves to the axial direction so as to make a switching operation of the first contact 218. Likewise, the second movable electrode 216 moves to the axial direction so as to make a switching operation of the second contact 219, and further, the third movable electrode 217 moves to the axial direction so as to make a switching operation of the third contact 220.
The gearbox 225 included in the disconnecting switch has been described above. However, in the conventional driving apparatus, the driving apparatus is required for a circuit breaker existing outside the figure. Thus, there is a need of providing an independent driving apparatus for each contact of apparatuses such as disconnecting switch and circuit breaker; as a result, the driving apparatus has been made into a large size. For this reason, the gas insulated switchgear is inevitably made into a large size. More specifically, in the above gearbox 225, one cam and two levers are required with respect to one movable electrode; as a result, the number of components is increased. Further, the number of components is increased; as a result, the structure becomes complicate, and manufacture assembly cost becomes high; therefore, this is disadvantageous in economization.
Moreover, when the number of components is increased, the apparatus configuration becomes complicate, and further, a space for receiving the gearbox 225 must be widened. More specifically, the metal container 222 for receiving the gearbox 225 and the grounding metal container 201 of the disconnecting switch 200 are made into a large size; as a result, the driving apparatus and the gas insulated switchgear are also made into a large size. When the apparatus is made into a large size, the cost is high; therefore, this is disadvantageous in economization.
In addition, in the driving apparatus, it is extremely important to secure an operation reliability. Thus, in order to secure the operation reliability, there is a need of assembling the complicate apparatus with high precision. However, when the number of components is increased, the apparatus configuration becomes complicate, and further, a work for assembling the driving apparatus becomes complicate; as a result, the work efficiency is reduced. Meanwhile, in the operation, maintenance and inspection, in the case where the apparatus configuration is complicate, the disassembling work for maintenance and inspection becomes complicate; as a result, there is a possibility of reducing the operability, maintenance and inspection performance when the apparatus is actually used.
The present invention has been made in view of the problems in the prior art. Accordingly, an object of the present invention is to provide a combined type fluid pressure driving apparatus, which can achieve small integration and simplification while securing high operation reliability, and has a switch made into a compact size.
Another object of the present invention is to provide a combined type fluid pressure driving apparatus, which is excellent in assembly, operation maintenance and inspection performance.
In order to achieve the above object, according to one aspect, the present invention provides a combined type fluid pressure driving apparatus comprising:
a metal container including a hollow support porcelain tube and a plurality of receiving porcelain tubes;
each contact of circuit breaker and disconnecting switch having a stationary electrode fixed in each of the receiving porcelain tubes, and a movable electrode received so as to freely separate from and close to the stationary electrode;
an insulating gas sealed in the metal container, the support porcelain tube and the receiving porcelain tube;
an insulated operating rod operated in the support porcelain tube;
a mechanical box arranged on the other end of the support porcelain tube;
a fluid pressure operating device received in the mechanical box and driven by fluid pressure; and
a connecting mechanism section provided in the metal container,
an operating force of the fluid pressure operating device being transmitted from the insulated operating rod to the movable electrode via the connecting mechanism section so that each contact of the circuit breaker and the disconnecting switch is switched (opened and closed).
In order to achieve the above object, according to another aspect, the present invention provides the combined type fluid pressure driving apparatus, wherein the fluid pressure operating device includes:
a plurality of fluid pressure cylinders switching and driving each switching contact of the circuit breaker and the disconnecting switch in accordance with feed and discharge of high-pressure fluid;
a plurality of fluid pressure control valves for independently driving each of the fluid pressure cylinders;
an accumulator for storing a high-pressure working fluid supplied to a plurality of fluid pressure cylinders and fluid pressure control valves;
a pump for supplying the high-pressure working fluid into the accumulator; and
a low-pressure tank for storing a low-pressure fluid discharged from the fluid pressure cylinders.
According to the above invention, a fluid pressure driving method is employed for readily achieving high output by high pressure, and therefore, it is possible to make compact the fluid pressure cylinder and the fluid pressure control valve, which are principal components of the fluid pressure operating device. Further, the accumulator, the pump and the low-pressure tank required for the drive are used in common between different apparatuses and the fluid pressure operating device. By doing so, it is possible to greatly reduce the number of components, and to achieve a simplification of structure.
In order to achieve the above object, according to another aspect, the present invention provides the combined type fluid pressure driving apparatus, wherein the fluid pressure operating device further includes: a circuit-breaker fluid pressure operating section for switching and driving a contact of the circuit breaker; a disconnecting-switch fluid pressure operating section for switching and driving a contact of the disconnecting switch; and a manifold forming the fluid pressure cylinder at the circuit-breaker fluid pressure operating section, and the manifold is removably attached with the accumulator, the pump, the low-pressure tank and the disconnecting-switch fluid pressure operating section.
According to the above invention, members such as the accumulator, the pump and the low-pressure tank, which are used in common between the circuit-breaker fluid pressure operating section and two disconnecting-switch fluid pressure operating section, are attached to the manifold of the circuit-breaker fluid pressure operating section side. Therefore, there is no need of providing connective pipe required for connecting two fluid pressure operating sections, and this contributes to integral combination of the driving apparatus. As a result, a design for saving a space is possible, and the driving apparatus can be made compact. Further, the member attached to the manifold of the circuit-breaker fluid pressure operating section is freely removable, so that a disassembling work for inspection can be simply carried out, and maintenance and inspection performance can be improved.
In order to achieve the above object, according to another aspect, the present invention provides the combined type fluid pressure driving apparatus, wherein the fluid pressure operating device includes: a circuit-breaker fluid pressure operating section for switching and driving a contact of the circuit breaker; a disconnecting-switch fluid pressure operating section for switching and driving a contact of the disconnecting switch, and the circuit-breaker fluid pressure operating section the disconnecting-switch fluid pressure operating section are connected with each other via a fluid pipe.
According to the above invention, in accordance with the layout of the plural contacts constituting the switchgear, a part or all of the disconnecting-switch fluid pressure operating section is arranged on the position far from the circuit-breaker fluid pressure operating section. In Such a case, the disconnecting-switch fluid pressure operating section and the circuit-breaker fluid pressure operating section are merely connected using pipe; therefore, it is possible to sufficiently secure a degree of freedom in design. Further, the accumulator, the pump and the low-pressure tank are used in common, and therefore, the fluid pressure driving apparatus can be made compact by integral combination.
In order to achieve the above object, according to another aspect, the present invention provides the combined type fluid pressure driving apparatus, wherein the apparatus is provided with a piston holding mechanism, which holds a position of fluid pressure piston sliding in each of fluid pressure cylinders when the high-pressure working fluid of the accumulator is lost.
According to the above invention, when the high-pressure working fluid of the accumulator is lost, the lock mechanism is operated so as to hold the position of the fluid pressure piston; therefore, it is possible to securely hold the switching state of contact. By doing so, it is possible to improve safety and reliability of the apparatus.
In order to achieve the above object, according to another aspect, the present invention provides the combined type fluid pressure driving apparatus, wherein the driving apparatus further includes: a driving rod extending from a fluid pressure piston fixed integrally with a flange; an expansible rod mechanism for expansibly connecting a support member fixed in the mechanical box with the flange; and an elastic element for elastically holding a position of the fluid pressure piston by an operating rod of the expansible rod mechanism.
According to the above invention, the making and breaking position of the fluid pressure piston is securely held by a load of compression spring regardless of the fluid pressure. Further, it is possible to visibly confirm the switching state of contact from the outside; therefore, inspection can be readily made.
In order to achieve the above object, according to another aspect, the present invention provides the combined type fluid pressure driving apparatus, wherein the driving rod extending from the fluid pressure piston and a support bracket fixed in the mechanical box are individually formed with an attachment hole aligned with each other, and a lock pin is inserted into the aligned, and thereby, a mechanism for holding the position of the fluid pressure piston is constructed.
According to the above invention, the lock pin is merely inserted into the hole of driving rod extending from the fluid pressure piston sliding in the fluid pressure cylinder, and thereby, the position of the fluid pressure piston can be held, and therefore, it is possible to carry out a work for holding the position of the fluid pressure piston by manual. Further, it is possible to visibly confirm the inspection, and thus, to improve safety and reliability.
In order to achieve the above object, according to another aspect, the present invention provides the combined type fluid pressure driving apparatus, wherein the fluid pressure operating device includes: a circuit-breaker fluid pressure operating section for switching and driving a contact of the circuit breaker; and a disconnecting-switch fluid pressure operating section for switching and driving a contact of the disconnecting switch, and a piston rod extending from the fluid pressure piston of the disconnecting-switch fluid pressure operating section is slidable, and a cylinder head fixed to one end of the fluid pressure cylinder is arranged in the gearbox, and further, the cylinder head is attached with a fluid pressure control valve.
According to the above invention, the constituent components are arranged so as to centralize in the cylinder head of the disconnecting-switch fluid pressure operating section, and therefore, the other end of the fluid pressure cylinder may be attached with only member for sealing a working fluid, and the structure can be simplified. Further, a relatively heavy constituent component such as the fluid pressure control valve is arranged on the position near to the upper fixed point. Therefore, it is possible to realize a structure, which is durable to an external force such as vibration by the operation and vibration by the operation of the circuit-breaker fluid pressure operating section having a relatively large driving force, and is excellent in vibration proofing and strength. In particular, the lower end portion of the circuit-breaker fluid pressure operating section opposite to the cylinder head is light; therefore, the fluid pressure cylinder is readily attached in the horizontal direction, and there is no limitation in the attachment direction. As a result, a degree of freedom increases in the layout.
In order to achieve the above object, according to another aspect, the present invention provides the combined type fluid pressure driving apparatus, wherein the fluid pressure operating device includes: a circuit-breaker fluid pressure operating section for switching and driving a contact of the circuit breaker; and a disconnecting-switch fluid pressure operating section for switching and driving a contact of the disconnecting switch, and an outer cylinder is concentrically arranged on an outer side of the fluid pressure cylinder of the disconnecting-switch fluid pressure operating section so as to form a double cylindrical structure, and further, an annular gap between the double cylindrical structure is used as a control fluid passage for feeding and discharging a high-pressure working fluid to and from a cylinder chamber of the fluid pressure cylinder.
According to the above invention, the control fluid passage is provided coaxially with the fluid pressure cylinder; therefore, this is advantageous to simplify the structure and to save a space as compared with the case where the fluid passage is arranged separately.
In order to achieve the above object, according to another aspect, the present invention provides the combined type fluid pressure driving apparatus, wherein the fluid pressure operating device includes: a circuit-breaker fluid pressure operating section for switching and driving a contact of the circuit breaker; and a disconnecting-switch fluid pressure operating section for switching and driving a contact of the disconnecting switch, and the fluid pressure cylinder of the disconnecting-switch fluid pressure operating section is attached to the cylinder head fixed in the mechanical box, and further, the fluid pressure control valve is arranged on the side opposite to the fluid pressure cylinder.
According to the above invention, the lower end portion of the circuit-breaker fluid pressure operating section needs to attach a member for sealing a working fluid, and the valve block of the fluid pressure control valve is used in common as the member, and thereby, it is possible to reduce the number of components, and thus, to simplify the structure. Further, the valve block is arranged on the cylindrical section of the fluid pressure cylinder; therefore, it is possible to make a design for making compact the driving apparatus without projecting the member into the radius direction.
In order to achieve the above object, according to another aspect, the present invention provides the combined type fluid pressure driving apparatus, wherein the fluid pressure operating device includes: a circuit-breaker fluid pressure operating section for switching and driving a contact of the circuit breaker; and a disconnecting-switch fluid pressure operating section for switching and driving a contact of the disconnecting switch, and one end of the fluid pressure cylinder of disconnecting-switch fluid pressure operating section is attached to the cylinder head fixed in the mechanical box, and the fluid pressure control valve is provided on the side opposite to the fluid pressure cylinder while an outer cylinder is concentrically arranged on an outer side of the fluid pressure cylinder of the disconnecting-switch fluid pressure operating section so as to form a double cylindrical structure, and further, an annular gap between the double cylindrical structure is used as a high-pressure fluid passage for always supplying a high-pressure fluid from the accumulator to the cylinder chamber of the fluid pressure cylinder.
According to the above invention, the high-pressure fluid passage is provided coaxially with the fluid pressure cylinder, and therefore, this is advantageous to simplify the structure and to save a space as compared with the case where the fluid passage is arranged separately.
In order to achieve the above object, according to another aspect, the present invention provides the combined type fluid pressure driving apparatus, wherein the fluid pressure operating device includes: a circuit-breaker fluid pressure operating section for switching and driving a contact of the circuit breaker; and a disconnecting-switch fluid pressure operating section for switching and driving a contact of the disconnecting switch, and a piston rod extending from the fluid pressure piston of the disconnecting-switch fluid pressure operating section is slidable, and a cylinder head fixed to the fluid pressure cylinder is fixed in the mechanical box, and further, the cylinder head is attached with a fluid pressure control valve so that an operating axis of the fluid pressure control valve and an operating axis of the fluid pressure piston are perpendicular to each other.
According to the above invention, an external force such as vibration by the operation of the fluid pressure piston and vibration by the operation and vibration by the operation of the circuit-breaker fluid pressure operating section having a relatively large driving force acts to the operating axis direction of the fluid pressure piston. In such a case, it is possible to prevent an erroneous operation of the fluid pressure control valve, and thus, to realize the structure, which is excellent in reliability.
In order to achieve the above object, according to another aspect, the present invention provides the combined type fluid pressure driving apparatus, wherein the fluid pressure operating device includes: a circuit-breaker fluid pressure operating section for switching and driving a contact of the circuit breaker; and a disconnecting-switch fluid pressure operating section for switching and driving a contact of the disconnecting switch, and at least one or more switching valve is provided on the midway of high-pressure and low-pressure fluid passages for connecting the circuit-breaker fluid pressure operating section with the disconnecting-switch fluid pressure operating section.
In order to achieve the above object, according to another aspect, the present invention provides the combined type fluid pressure driving apparatus, wherein the fluid pressure operating device includes: a circuit-breaker fluid pressure operating section for switching and driving a contact of the circuit breaker; and a disconnecting-switch fluid pressure operating section for switching and driving a contact of the disconnecting switch, and the high-pressure and low-pressure fluid passages for connecting the circuit-breaker fluid pressure operating section with the disconnecting-switch fluid pressure operating section are formed of a flexible pipe, and further, a connector with at least one or more check valve is provided on the midway thereof.
In order to achieve the above object, according to another aspect, the present invention provides the combined type fluid pressure driving apparatus, wherein the fluid pressure operating device includes: a circuit-breaker fluid pressure operating section for switching and driving a contact of the circuit breaker; and a disconnecting-switch fluid pressure operating section for switching and driving a contact of the disconnecting switch, and the circuit-breaker fluid pressure operating section or the disconnecting-switch fluid pressure operating section is connectable with an auxiliary fluid pressure source including at least one or more electrically-operated or manual pump.
In order to achieve the above object, according to another aspect, the present invention provides the combined type fluid pressure driving apparatus, wherein the fluid pressure operating device includes: a circuit-breaker fluid pressure operating section for switching and driving a contact of the circuit breaker; and a disconnecting-switch fluid pressure operating section for switching and driving a contact of the disconnecting switch, and the circuit-breaker fluid pressure operating section or the disconnecting-switch fluid pressure operating section includes an auxiliary fluid pressure source including at least one or more electrically-operated or manual pump, and the an auxiliary fluid pressure source is provided with an electrically-operated or manual pump, an accumulator for storing a high-pressure fluid and an auxiliary tank for storing a low-pressure fluid.
According to the above invention, even if the fluid pressure of the combined type fluid pressure driving apparatus is reduced, it is possible to provide the combined type fluid pressure driving apparatus, which can readily perform various works such as inspection and repair of the fluid pressure operating section, replacement work and recovery work of fluid pressure without stopping the transmission line.